Observation of spin textures in La1−xSrxMnO3 (x = 0.175)

Abstract

We have investigated topological spin textures in the ferromagnetic metallic phase of La0.825Sr0.175MnO3 with the centrosymmetric crystal structure by small-angle electron diffraction (SmAED) and low-temperature Lorentz transmission electron microscopy (TEM) experiments. In-situ Lorentz TEM and SmAED experiments revealed that type-I and type-II magnetic bubbles evolved from magnetic stripe domains with the Bloch-type domain wall by applying vertical magnetic field. Type-I magnetic bubbles with left-handed and right-handed spin helicity were randomly distributed and simultaneously type-II magnetic bubbles are formed locally. The important point about type-I and type-II magnetic bubbles is that their emergence depends strongly on whether perpendicular magnetic field is applied parallel to the magnetic easy axis along the [001] direction. Our experimental results suggested that the stabilization of magnetic bubbles should originate from the long-range dipole-dipole interactions, as opposed to the Dzyaloshinskii-Moriya interaction in helical magnets.

Field-temperature phase diagram of magnetic bubbles spanning charge/orbital ordered and metallic phases in La1−xSrxMnKotani1, Nakajima2, Harada3 et al. 2017Phys. Rev. BSelf Cite21150View full textAdd to dashboardCite

“…3(a). As we have previously reported, type-I magnetic bubbles possess a bright point at their core in the FM-M phase of La0.825Sr0.175MnO3 at 90 K [26][27][28] in Fig. 3(d).…”

“…The residual magnetic field in the objective lens of the TEM was observed to be less than 20 mT. The spatial configuration of the spins in the magnetic stripe domains was observed to be the same as that in the FM phase of La0.825Sr0.175MnO3 [26]. A significant feature observed in the domains was the formation of zigzag walls, as shown in the inset of Fig.…”

“…In a previous study, we investigated magnetic bubbles in the FM-M phase of La1−xSrxMnO3 for x = 0.175, which had an orthorhombic structure with inversion symmetry; we used in situ Lorentz microscopy (LM) observations combined with smallangle electron diffraction experiments [26,27]. We found that magnetic textures such as magnetic bubbles and magnetic stripe domains appeared in La0.825Sr0.175MnO3, and they depended significantly on the magnetocrystalline anisotropy.…”

Emergence of Topological Hall Effect in Half-Metallic Manganite Thin Films by Tuning Perpendicular Magnetic Anisotropy

“…derlying helicity degree of freedom [16,17]. Furthermore, the skyrmionic bubbles can form only in single-phase bulk crystals [18][19][20][21][22][23][24], but also in thin film multilayers, sometimes in conjunction with DMI [25][26][27][28][29][30][31]. The wide variety of materials choice is a major advantage of the skyrmionic bubble from the application point of view.…”

Variation of Topology in Magnetic Bubbles in a Colossal Magnetoresistive Manganite

“…[3,4] (2 of 6) 1603958 different size were observed in a previous LTEM study. [27,28] Here, we tried to capture the change of topological magnetization textures and their dynamics by means of LTEM imaging as the temperature or magnetic field is varied, which demonstrated the following evidence: i) formation of bubble lattice after FC and transition from skyrmionic bubbles to 180° in-plane FM domain structure associated with the change of magnetic anisotropy upon the structural transition; ii) presence of bubbles with different internal structures or BLs; iii) the motion of BLs and resultant change in the internal structure and topological number of the skyrmionic bubbles induced by in-plane magnetic fields of a few tens of milliTesla. [26] Most recently, the bubbles with ≈ 300 nm in diameter have been observed in thin plates of x = 0.175.…”